Improvement in the manufacture of iron and steel



UNITED STATES PATENT OFFICE.

GEORGE HAND SMITH, OE NEW YORK,4 N. Y.

IMPROVEMENT IN THE M-AN-UFACTURE OF IRON' AND STEEL.

Specification forming part of Letters Patent No. 105,267, dated July 12, 1870.

To all whom it may concern:

Be it known that I, GEORGE HAND SMITH, of the city, county, and State of New York, have invented a new and Improved Process for the lllanufacture of Iron, Steel, and other metals; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, making part of this specification, in which- Figure l is an elevation of a furnace suitable for the working of my said process; Fig. 2, a longitudinal vertical section 5 Fig. 3, a cross vertical section taken at the line A a of Fig. 4, and Fig. 4, a horizontal section taken at the line B b of Fig. 3.

The same letters indicate like parts in all the figures.

The leading object of my improved process is to obtain iron or steel of any desired grade direct from the Oxide ores of iron, but the said process may be used for Obtaining other metals from their ores, if oxides of such metals, except suoh as zinc, which vaporize at too low a temperature. And my said process may also be used for obtaining blooms or masses of iron or steel suitable for the hammer or rolls from scraps, or from what is known as iron or steel spongeL-that is to say, iron ore which has been deoxidized, or deoxidized and carbonized.

My said invention consists in condensing the metal or partially formed metal under treatment by the weight of the charge, by subjecting the ore or sponge, or scraps of pig or crude iron, in a vertical tube or tubes, and applying the heat through the walls of such tube or tubes, so that when it becomes plastic by heat the weight of the upper part of the charge shall condense the lower and most highly-heated portion, and thereby obtain the mass in a better condition to be afterward heated to a Weldingheat; and my said invention also consists in passing such condensed mass directly from the tube or tubes in which it has been condensed into another tube or series of tubes, in which it is brought to a high welding-heat, preparatory to hammering or rolling; and my said invention also consists in deoxidizing and carbonizing oxide ores by receives the products of combustion at c from a suitable fire-chamber, d, and after such products of combustion have circulated around the said tubes they escape into a chimney, e. The said tubes rest on arches f, which form the bot-tom ofthe chamber b, and below the I said arches the lower open ends of the said tubes are provided with Asuitable hinged bottoms g, on which the charge of ore or metal under treatment rests, and by the opening of which the condensed portion of the charge is delivered.

rEhe ore to be treated and carbonaceous mat ter are charged into vthese tubes through their upper open ends, that are on alevel, or nearly so, with the roof h of the furnace. At an elevation of about one-fourth their height from the lower end, a horizontal slot, t', is formed in each of the said tubes, through which a cutoff, j', oan'be introduced, to separate the lower part of the charge, so soon as it has reached the required condition, from the upper part of the charge, and to hold up the upper part of the charge until the lower part, which has been thus cut Off, is discharged through the hin ge-bottom g and, after such discharge, and the bottom g has been closed, the cut-off j is Withdrawn, to permit the upper part of the charge to descend. These slots may be closed by any suitable means during the working of the process.

What is termed the cut-off77 is a steel knife with a handle, so Vthat when inserted with suficient force it will cut through the charge, which, at the time, has been reduced to a somewhat plastic state.

Below the lower end of the tubes a there is an interposed chamber, j, formed between the arches f, and a corresponding series of arches, k, below; and below the arches k, and extending4 up through to the upper surface thereof', there is a series of short tubes, Z, corresponding in number with and immediately below the vertical tubes a. The lower ends of these tubes Z rest on a floor, m, made of iron and covered with lire-brick; and the chamber u, in which these tubes are placed, communicates at one end with the lire-chamber d, and at the other end with the chamber b, in which the tubes a are placed, so that the products of combustion from the fire-chamber, after passing over the rire-bridge o, circulate among the short tubes l before passing up into the chamber b to act on the tubes a..

The upper ends of the short tubes lare provided each with a sliding cover or slab, p, to prevent the entrance of air to the inside; and at their lower ends they are provided each with a hinged bottom, q, for the discharge of the contents when required.

Having described the kind of furnace which I deem suitable for the working of my said process, I will now describe the preferred mode of working the said process.

If I desire to manufacture wrought iron or steel, the oxide ore of iron is comminuted and cleansed in the usual way, and in admixture with charcoal or other suitable carbonaceous matter charged into the vertical tubes a to the top, the hinged bottom g being closed, and the upper ends covered with slabs. After being so charged, the heat is applied, the products of combustion circulating around the tubes and heating the charge, not by actual contact, but through the walls of thetubes. In this way the oxide is gradually extracted from the ore, which is thereby reduced to what may be termed sponge,7 the weight of the upper part of the charge gradually condensing the lower part, where the heat is greatest, and where the particles of metal become plastic at low red heat.

/Vhen the lower part of the charge has been brought to a red heat and sufficiently condensed, the cut-offj is introduced in each of the slots t in the tubes and forced through the charge, to separate the lower part of the charge from the upper part, and then the slides or slabs 19, which cover the lower series of tubes l, are removed, the hinged bottoms g are opened, and the masses so separated permitted to drop into the lower tubes, l, which are there inclosed, the bottoms ofthe upper tubes, a., are closed, the cutoffs withdrawn, and the charges permitted to descend for a continuation of the process.

As the lower tubes are heated by the products of combustion from the fire-chamber before passing into the upper chamber, b, the masses so transferred to the lower tubes will be there heated to a welding-heat; and when brought to the required heat they are discharged and subjected to the action of hammers, hydrostatic press, jaws, rolls, or other suitable means, as in the case of puddle-balls, to reduce them to blooms. The lower tubes, when emptied, are ready for receiving other masses of condensed sponge from the upper tubes, the charges in which must be replenished as often as required.

lf the objectbe to make steel, the charge of carbon must be proportioned to the percentage of oxide in the ore, that, after eX- tracting all the oxide, there shall be sufficient carbon left to carbonize the deoxidized ore to the degree required for the grade of steel desired to be produced.

If desired, the masses of condensed sponge, instead of being discharged into the lower tubes, to be there brought up to a weldingheat, may be so heated in a puddlin g or other separate furnace; but the required result will be best obtained by the mode first described.

Instead of using carbonaceous matter in the pulverized state, in admixture with the oxide ores, it may be introduced into the tubes in the gaseous form during the working of the process.

If the upper tubes be made of material sufficiently refractory, the whole process may be worked without the lower set of tubes, by applying sufficient heat to brin g the lower and condensed portion of the charge to a high welding-heat before cutting it olf, and discharging it in a suitable condition for the hammer, hydrostatic press, rolls, 85e., the leading part of my improved process being to get the lower part of the charge in a condensed and aggregated mass, whether such aggregated and condensed mass be discharged from the first tube or set of tubes at a low red heat, and then transferred into the lower set of tubes, to be there heated to a high weldingheat, or the aggregated and condensed mass to be heated to a welding-heat in the upper tube or tubes. And it will be seen that this part of my said invention can be applied to the treatment of pig or crude iron for the production of wrought iron or steel, by introducing in the tubes charged with pig or crude iron any of the deca-rbonizing agents, to extract the whole or part of the carbon, the mass being heated and treated in all other respects as in the case of ores, sponge, or scraps.

The several tubes should be made of plumbago and clay, or other refractory substance."

What I claim as my invention, and desire to secure by Letters Patent, in the process of preparing iron or sponge or pigiron lfor the hammer or rolls, or equivalent means, is

l. Charging the scraps, or sponge, or pig-iron in a vertical tube (one or more) provided with a movable bottom, and applying the heat through the walls of the tube, substantially as described, whereby the mass is heated without exposure to atmospheric air or the gaseous products of combustion, and as the particles become plastic the mass is condensed by the weight of the charge, as set forth.

2. Also, the process, substantially as described, for deoxidizing oxide ores, and, if rethe after treatment, to bring the condensed quired, carbonizing the resulting metal, by masses to aWeIding-heat, substantially .as-de# charging the oxide ores or sponge with carscribed. bonaceous matter in a vertical tube (one or GEORGE HAND SMITH. more) having a movable bottom and a cut-off', Witnesses:

and applying the heat through the Walls ofthe ANDREW J. DE LACY,

tube or tubes, as set forth, in combination with A. B. BISHOP. 

